124 Scientific Intelligence. 
11. Fluoride of Calcium in Cannel Coal ; by H. D. Rocers, (Proceed. 
Bost. Nat. Hist. Soc. p. 109, March, 1846.)—Prof. Rogers remarks that 
the English Cannel coal, which he had been using in his grate, often dis- 
persed over his apartment, with a violent crepitation, small fragments 
of fluor spar. Some. of the fragments were more than half an inch in 
diameter. Afterwards, upon breaking a piece of'the coal, he detected 
a small isolated crystal of this mineral. Prof. Rogers suggests that 
the elements of this mineral: may have been derived from the coal 
vegetation ; adding also, that it is possibly due to volcanic agency’ be- 
low, setting at liberty vapors of hydrofluoric acid. 
12. Petrified Wood in Texas; by J. Luuzer, (in a letter dated, In 
dependence, Texas, April 24, 1846.)—In this region, and especially 
north of this, pieces of wood, petrified, are found in great quantities. 
In some localities, stumps of trees three feet through, pieces of trunks 
of trees of the same size, and from two or three to twenty feet long, 
cover the whole face of the ground, Magnificent specimens might be 
obtained for cabinets. Should any institution wish a specimen, and will 
write to me, I will take a pleasure in procuring for them, specimens of 
such size as they will specify. The expense of transportation would not 
be great, as they could be taken down the Brassos to the Gulf of Mexico, 
aud thence to any part of the United States by water. *%y 
13. Falkland — ; by C. Darwin, (Atheneum, No. 965.) —The 
low lands of the Falkland Islands consist of clay slate, containing sub- 
ordinate leieis ae sandstone, and the slate occasionally, though rare+ 
ly, and the sandstone more commonly, give indication of fossils, 
which Prore ae existence of — rocks in these southern regions. 
Th The slaty 
o 
Pe ds oe “4 r voy oe 
and Sousilittncaal of ‘jslands are broken east and 
west — of stratified q quaetay nanny) sometimes a heh of 2 i 
gt Tertiary of Waris Co: tg Mississippi ; ; by T. A. Conia 
(Communicated for this Journal.)—While collecting the organie’re- 
mains of Warren county, Mississippi, I noticed a few shells which ap- 
peared to be identical with species from Claiborne, Alabama, but since 
I have carefully compared them in my cabinet, they prove. to be dis- 
tinct ; and it is very remarkable that of the one hundred and three 
species of fossils found near Vicksburg, not one can be identified with 
a species of the Eocene of Maryland, Virginia, or Alabama, There:is 
a species of Trochus resembling T’. agglutinans;: but the specimen is 
too imperfect to decide whether it sane with the fossil T. agglutinans 
ped Georgia. The Vicksburg group h has decidedly more. affinity vith the 
tht closely. resembles “a denseaeraie The “limestone. of Clarke 
